How to Fix a Cracked Basement Wall

A long, horizontal crack in a basement block wall may indicate a dangerously weakened wall.

Cracks in basement walls are common, but they can also be a sign of a weaken wall. We'll tell you how to handle this potentially dangerous wall before it leads to structural problems with your house. It's a problem that must get fixed before you finish your basement.

By the DIY experts of The Family Handyman Magazine:July / August 2004

Time

One day

It'll probably take a day or more to get a pro to inspect the wall.

Complexity

Complex

You'll probably need to call in a pro to help with this project.

Cost

Step-by-Step

Cracked basement walls

This basement has a crack running horizontally along the block concrete wall. There's also a stair-step crack on each end of the horizontal crack, and the wall is bowed in about 1 in. You can't handle this cracked wall by simply filling the crack and finishing off the basement. If you only had the stair-step cracks, you could go ahead with your basement finish work, because that type of crack is a normal sign of settling. Stair-step cracks may cause cracks in other walls above or a door to rub, but they don't compromise the strength of the foundation.

However, the horizontal crack that has bowed the wall inward is the sign of a severely weakened wall that can fail. Even if it has been stable for awhile, it can no longer reliably support the load it's supposed to carry. If your basement has this problem, our advice is to ask a local general contractor or building official to direct you to a structural engineer who can examine the wall and surroundings and suggest the correct method to reinforce the wall.

Tools & Materials List

Required Tools for this Project

Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.

No tools are needed for the inspection. The tools needed for the fix depend on what's recommended by the structural engineer.

Required Materials for this Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.

The materials will depend on the fix recommended by a structural engineer.